Food intolerance is a complicated business and replacing nutrition lost on an exclusion diet may involve 'going exotic'.

Margaret Moss explains

One of the most important things to know about foods is that they are complicated. They contain a mixture of substances, some good and some bad. One food can help you and harm you at the same time. Processing foods may be helpful if it removes harmful substances, and harmful if it removes useful nutrients. Exotic foods may add variety to the diet, but we do need to know how to use them.

Some of the complications

You may be told to avoid some foods, and then to try one food at a time. If you react to it, then avoid it. If you do not react to it, you are fine. Well no. Sometimes you don’t react to a food, because your body has had a rest from it. If you keep on having the food, then your body may start protesting. Also you may cope with one apple, but a different variety of apple, an apple grown on a different soil, or a larger apple may be too much for you. Maybe a cooked apple is alright, but not a raw one. Maybe the apple is alright peeled, but not unpeeled. Maybe an organic apple is acceptable, but not one sprayed on the tree, or dipped into a preservative after it is harvested.

Quantity may be important

Maybe you are reacting to a certain chemical in one food, which is in other foods too. Some people I know do not tolerate a lot of beta carotene. One tomato, half a carrot, half a mango, a quarter of a pepper, 25g of Double Gloucester, or 50g of broccoli alone may not be a problem, once a week. However, if every day they eat apparently healthy meals, like cheesy pasta in tomato sauce, with spinach and orange sweet potatoes, followed by a large mango, then they will land in trouble.

Table sugar is sucrose, a mixture of glucose and fructose, or fruit sugar. You may be able to eat one apple, or one orange. However, you may have difficulty absorbing all the fructose, from a party meal, with cake, icing, trifle, and sweet drinks. The fructose that you do not absorb from the gut into your bloodstream can feed unwanted bacteria in the gut, making you gassy, and giving you diarrhoea. Alternatively, you may be able to absorb all that fructose, but not to process it. Fructose also converts to triglycerides, fats that add to your body weight, or make your liver fatty.

Ancestry may also be relevant

Many people whose ancestors evolved in hot countries have limited capacity to break down the double milk sugar, lactose, into the simple sugars, glucose and galactose. Some of my students in Kenya could cope with a mug of tea with a little milk in, for breakfast, followed by a mug of cocoa, with a little milk in, at break-time. If the milk arrived late, and they were given black tea for breakfast and all the milk was put in the cocoa, they could not tolerate so much lactose all at once. Some people buy the lactase enzyme, in order to be able to break lactose into glucose and galactose. In the short-term, this is a solution, but galactose damages arteries, and is better avoided. Milk that has been treated with the enzyme, in order to break down the lactose before you drink it, is not a good idea either.


Foods interact. An enzyme in lettuce and celery releases the cyanide from maize and millet. So you may be able to eat lettuce and celery in a salad. You may be able to eat maize or millet porridge. However, when you have a salad with celery, lettuce and sweet-corn in it, you may not have enough of the rhodenase enzyme to deal with the cyanide released. A little cyanide is toxic to cancer cells, but too much is toxic to us. The amount people tolerate varies, depending on their rhodenase.

A girl could tolerate peaches, and she could tolerate ice-cream. When she ate the two together, she went into anaphylactic shock. It seems that the cold of the ice-cream prevented her from processing a chemical in peaches. Maybe the necessary enzyme could not function at a cold temperature.

Our state of health is important

There are times when we are more susceptible to reactions. Perhaps premenstrual syndrome, or being menopausal, makes us more susceptible. Perhaps a particular pollen is irritating us, so that we are then less able to cope with a food. A chemical in birch pollen is similar to one in apples, pears, carrots, almonds, coriander and some other foods. So some people become more reactive to apples in the birch pollen season. Babies who have had gastroenteritis may lose their ability to break down lactose temporarily.

Three pre-conditions?

Sometimes there must be three conditions for a reaction to happen. For example, maybe you can drink milk, you can be premenstrual, and you can be exposed to a particular pollen. However, when all three things happen at once, the burden on your body is too much, and you have a reaction.

Processing aids may be the problem

Manufactured foods contain a mixture of chemicals, some on the label and some not. Some items do not have to be declared, and some may be present illegally. For example, some sugar may be added to “unsweetened fruit juice.” Some high fructose corn syrup is manufactured in a process that leaves some mercury in the syrup. Solvents may be used to remove caffeine from coffee and tea. Decaffeinated drinks may contain some residual solvent. Someone came to see me, saying that she was sensitive to chilli, which she may have been. However, each of the three items that set off a reaction were processed. Red dye has been used instead of chilli in some products. It is possible that it was in the foods she bought, without being included on a label.

Enzyme preparedness

Alcoholics admitted to hospital, and refused their alcohol fix sometimes cope easily with drugs the hospital gives them. This is because they have enzymes waiting to detoxify alcohol, and they are available to deal with the drugs instead. Similarly, if we eat a certain food all the time, or one containing a similar chemical, we may be able to eat it without problems. But if we do not eat that food for a while, or one with a similar chemical, we may find we cannot tolerate the food, because we had had no reason to make the enzyme.

Dairy intolerance

Often people say that they cannot eat dairy foods. The question then is which ones? Milk contains sugar, protein and fat. If the sugar is a problem, you may be able to eat hard cheese that has been pressed, and all but a trace of the sugar removed. If the protein is a problem, you may be able to eat butter, but not cheese. If you have a leaky gut, the butyric acid in butter is healing.

Problems with bread?

Wholemeal bread may cause you a problem, because of the lectin in it. You may find refined flour acceptable. Bread used to be made from fermented wheat. Wheat soured by certain bacteria makes a sourdough bread that can be tolerated by some wheat sensitive people, and even some coeliacs, as the bacteria break down the protein in the grain. Ciabatta is sourdough, and some other breads are more sour than ciabatta. Of course you need to be careful when trying out such bread, if you are very wheat sensitive. You also need to make sure the bread has not been placed on unfermented flour before it was cooked.

Beans, lentils and chickpeas

Those sensitive to whole beans and lentils may be able to tolerate red, yellow mung or white lentils, from which the skins have been removed. Chickpeas are a vetch, not a pulse, and are to be avoided, as they can damage bone and the nervous system. When there is drought in India and only chickpeas harvested, eating too much of them can cause epidemics of paralysis.

Replacing nutrition lost on an exclusion diet – go exotic!

If you are sensitive to a particular food you may wonder how to replace the nutrition it provides with tasty healthy foods. It may help to use foods from distant lands. Finger millet is a delicious small grain, one of the few significant plant sources of calcium, and so good for growing children who avoid milk. We used to eat it when I lived in Africa. I didn’t realise it is eaten in India, and that the Indian name is ragi. I found some whole ragi and ragi flour in Asian shops in Manchester, but I am still hoping to find some ragi meal, as a coarser meal would be better for making porridge. Finger millet makes the most tasty porridge I know. Squeezing a lemon or lime in it, after cooking, makes it smooth.

Preparing exotic foods

When eating exotic foods, we need to learn the pitfalls. Don’t eat the part of a mango near the stalk. There is a harmful chemical in it, and it can give people diarrhoea. Cut off the two cheeks, and use a sharp knife to cut through the flesh in parallel lines, and then more lines at right angles. You can then eat it with a small spoon, as though you were eating grapefruit. You can then cut the skin off the remaining piece, and cut pieces off it to eat, avoiding the bit near the stalk.

Cashews are one type of nut that needs cooking. If you buy raw cashews, you should put them in a dish in a moderate oven for five minutes, take the dish out, stir the nuts, and then cook them another five minutes. They should be lightly coloured, but not brown.

Chou chou is a delicately flavoured vegetable that grows on a vine in Africa and Caribbean countries. Cut it in half, throw away the soft stone, peel it, and dice the flesh. Boil it for about ten minutes, until it is soft.

If you are able to buy very green bananas, they make a tasty alternative to potatoes. If possible buy fat ones. Peel them with a knife, and boil and mash them. Plantains are larger, and a slightly different shape. They taste best if bought yellow. Peel them Melt some butter or coconut oil in a covered frying pan. Slice the plantain onto the fat. Add about a centimetre of water. Cook them for about ten minutes with the lid on, until they are soft. Eat them instead of potato. They taste quite different from the green bananas. If you can’t have ice-cream, try freezing liquidised ripe banana. Try liquidising bananas and blueberries together, and chilling them for a dessert.

Avocadoes are tropical fruits, and they do not want to be refrigerated, or they can go off before they ripen. Try to buy them from shops that have not stored them in a cold room.

Buckwheat is not a grain, and can be a useful food for those on gluten free or grain free diets. I asked a Russian student how it is cooked in Russia. She said that you boil a cupful of whole buckwheat in 2 cupfuls of water. Then you take off your coat and spread it on the table!  You cover it with paper, put the pan on the paper, and wrap the coat round it. After an hour, she says, it is delicious. It sounds like using a hay box. In Kenya we cooked the school polenta, and then switched off the gas, allowing the large quantity of polenta to continue cooking. It is the same principle. Those who can eat rice could also cook white rice with buckwheat, adding coconut oil and a little vegetable as flavouring, maybe onion, leek or tomato. Then spread it on a buttered tray, and roast it like flapjack.

Make use of local expertise

Supermarkets employ shelf stackers from many lands. They could ask their staff to develop educational resources for the customers, using their combined knowledge of foods.

Classical allergy involving the antibody, IgE may make you sensitive to tiny amounts of allergen. For those with food sensitivity caused by enzyme defects, traces of the food are usually well tolerated. Food intolerance is often a problem of body chemistry, rather than immunology. Beware the idea that food sensitivity is all about the antibody, IgG. We make IgG to help us process foods.

I like my clients to explore exotic cuisine, rather than just feeling they have to buy foods made for people with problems. I call my little book of recipes and information “Good Food for Special People,” as that is more positive than “Recipes for Allergies,” or some such.

Margaret Moss MA UCTD DipION CBiol MIBiol

First published November 2013


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